EIS is a powerful technique used in electrochemical experiments, but to be sure the measurements will be valid, your systems needs to fulfill various requirements:
1. your system needs to be linear;
2. your system needs to be in steady-state regime;
3. the values of the parameters defining the system should not be changing throughout the experiment.
Since real electrochemical experiments does not fulfill to these requirements, Bio-Logic has introduced the EIS quality indicators. These indicators can be used to that give quantitative information on the quality of electrochemical impedance measurements and help finding the best input parameters.